Been fooling around with the TV linkage on my 65 Nova and found
that making the arm longer makes the shift point higher. Here's what I did and like the shift points much better.
Disconnect the TV linkage and hold it as far in (or down) as it will go. Then hold the throttle wide open and adjust the TV linkage to go right into the hole while holding the TV and throttle as mentioned above. Now turn the TV nut out 10 full turns and try it at this point. This is where mine is and I like the shift points.

The problem I have is when it down shifts to first. It down shifts at about 10-12 MPH but it bangs real hard...almost like the rear end is sloppy. If I manually down shift at a little higher speed (like 15-20), it seems perfect. Any suggestions?